Tracer and automatic pattern feed



Dec. 14, 1948 Filed April 19, 1945 I w. L. TANCRED 2,456,158

TRACER AND AUTOMATIC PATTERN FEED 2 Sheets-Sheet 1 INVENTOR.

Dec. 14, 1948. w. L. TANCRED TRACER AND AUTOMATI C PATTERN FEED 2Sheets-Sheet 2 0 Filed April 19, 1945 INVENTOR. BY 7/ zZ/ zm I 247201245May,

Patented Dec. 14, 1948 TRACER AND AUTOMATIC PATTERN FEED William L.Tancred, Springfield, Vt., assignor to Jones & Lamson Machine Company,Springfield, Vt., a corporation of Vermont Application April 19, 1945,Serial No. 589,229

8 Claims.

This invention relates to tracer mechanism such as may be employed tocause a tool to operate on work to a contour determined by a patterntraced by the tracer mechanism.

One object of the present invention is to provide an automatic controlof the speed of relative motion between the work and tool and betweenthe tracer and pattern in accordance with a predetermined program. Forexample, such speed may be relatively high during idle or non-cuttingrelative motions between the tool and the work, slower where the toolmay be cutting along the less complicated contours, and still slowerwhere the contours are more intricate.

A further object of the invention is to provide for an automatic feedbetween a control pattern and tracer with a corresponding feed betweenthe tool and the work for each new tracing cycle.

A still further object of the invention is to provide as a portion ofthe control pattern a shield for the final pattern which isprogressively retracted toward an edge of the final pattern insuccessive tracing cycles and forms with the exposed portion of thepattern edge during any cycle, a control contour'for the shape of thetool path during that cycle. By this means the tool may progressivelyconform to a more intricate pattern edge more and more as the contour ofthe work approaches the final contour desired, which is that of thefinal pattern, the tool cutting a straight path where it is controlledby the shield to remove a considerable amount of stock so that thecutting is uniform and as the stock becomes removed more and more, thefinal pattern contour takes over more and more of the control until thetool is controlled entirely by the pattern edge, at which time theshield is in position to entirely uncover the pattern edge.

For a more complete understanding of this invention, reference may behad to the accompanying drawings in which Figure 1 is a somewhatdiagrammatic cross sectional View on line [-4 of Figure 2 of a tracermechanism embodying a portion of the invention.

Figure 2 is a longitudinal sectional view on line 2-2 of Figure 1.

Figure 3 is a detail sectional view on line 3-3 of Figure l.

Figure 4 is a diagrammatic view of a portion of the hydraulic system,

Figure 5 is a plan view, partly broken away and in section, of thepattern support and feed mechanism, a portion of the tracer being shownin cross section.

Figure 6 is a side elevation, partly broken away and in section, of theparts shown in Figure 5.

Figure '7 is a detail sectional view on line 1-1 of Figure 5.

Figures 8 and 9 are end elevations of the mech-- anism shown in Figure5, but with the end cover off and on, respectively.

Figure 10 is a fragmentary perspective view of a speed controlling cam.

Figure 11 is an exploded perspective view of a portion of the patternfeed actuating mechanism.

Figure 12 is a somewhat diagrammatic top view, a portion of the tracerbeing shown in section, showing the tracer mechanism and pattern controlas applied to a lathe.

Referring first to Figures 1 to 4, at i is shown a support to which isfixed a tubular casing 2.. One end of the casing 2 is shown as ofreduced diameter as at 3, and near the lower extremity of this portionit is bridged across by a diaphragm 4, which forms a fulcrum means foran inner tracer element 5. The diaphragm 4 is provided with slotstherethrough through which extend fingers 6 projecting from the lowerend of an outer tracer element 1. This outer element 1 is provided witha fulcrum diaphragm 8 somewhat similar to the diaphragm 4 and whichextends between it and the casing 2 and its outer margin may be heldagainst an internal shoulder 9 of the casing as by a clamping ring H). v

Normally the element-s 5 and 1 are concentric to each other, but theymay be displaced from such relation by engagement of a feeler l2 securedto the lower end of the element 1 against the edge I3 of a controllingpattern contour-sedge which will later be further described. The lowerend of the element 5 is formed as a head M which rides within andslightly spaced from a circular flange l5,which, as shown, forms a partof the feeler E2, The partsare so arranged that when the feeler 1'2 isdisplaced laterally, as by engagement again-st the pattern edge 13, itsfirst motion is a pivotal motion about the diaphragm 8 as a fulcrumuntil the flange I5 contacts with the head 14. Thereupon further lateralmotion of the feeler moves the lower end of the element 5 with it, butas this element 5 is pivoted at the diaphragm 4 much closer to its lowerend than is the element 1, the upper end or the element 5 is moved inthe same direction as the upper end of the element 1 but with a greatlyincreased amplitude. The result is that the first movement of the tracerelement 1 unaccompanied by any motion of the'-e1e-. ment 5 produces arelative motion of the upper ends of the elements 5 and 1 inone'directipn while a further movement of the feeler after contact ismade with the element 5 moves the element 5 at a much faster rate thanthe element 1 so that the upper ends of these elements move in arelative direction opposite to that before contact between the feelerand the element 5 was made. These relative motions between the upperends of the elements 5 and I are taken advantage of to controllongitudinal and transverse feeding motors which move the tracerrelative to the pattern. For example, in Figure 1, a hydrauliclongitudinal motor is shown at 20 and in Figure 4, a cross slide motoris shown at 2!.

For the purpose of controlling the motors by this relative lateralmotion of the upper end portion-s of the tracer elements 5 and l, a pairof valve mechanisms 25 and 26 are illustrated. Each of these valvemechanisms comprises a spool valve 30 and each of the spool valves rideswithin an axially movable sleeve 3|. Each sleeve has ports 33, 34 and 35which more or less overlap valve casing passages 36, 3'! and 38,respectively. The central casing passage 3'! is connected to a pressurepassage and pipe 40, which is supplied with fluid under pressure fromameans shown somewhat diagrammatically in Figure 4. Referring to thisFigure 4, fluid is taken from a supply tank 4| through a filter 42 by apressure pump 43 operated by an electric motor 44. The pump 43 deliversinto a pipe 45 to an accumulator 46 from which delivery is made to amain controlling valve 41 through the pressure pipe 48. A pressurerelief valve 49 connects from the pipe 45 back to a discharge pipe 50which thus provides for relief of any excess pressure beyond thatdesired in the pressure pipe 48. The valve casing 41 has a' valve 52therein, which in'the position of adjustment shown, permits the passageof fluid under pressure from the pipe 48 into the pipe 45 leading to thetracer mechanism. By moving the valve 52 to the right, it will beevident that the pipe 40 may be cutoif from its source of pressure, andthe fluid allowed to circulate back through the pipe 53 and a lowpressure relief valve 54 to the discharge 50 Whenever it is desired tocut out the tracer from operation. This is operated'by a control lever55.

The tracer mechanism, including the casing I, is carried by a carriage60, which as shown diagrammatically in Figure 12, may be the cross slideof a lathe, this cross slide being mounted on a longitudinal slide Bl.The cross slide is adapted to carry .a tool 62, as in a turret 63, foroperating on work 64 carried by a rotary chuck 65. The motor cylinder 20is arranged to move the longitudinal slide, and the motor 2| is arrangedto move the cross slide.

The central tracer element 5 is arranged to control the positions of thevalves 30, and to this end, a pair of yokes l and II are arranged tostraddle the upper portion of the tracer element 5. Each of these yokesis pivoted as on one of a pair of ears 12 to the inner face of thecasing 2 and each has an arm 13 which is connected through a flexiblelink 14 with one of the valves 30. The upper end of the tracer element 1is formed as a circular flange l and this is connected at two pointsthrough the flexible links 16 with the sleeves 3i. The ports 33, 34 and35 of each of the sleeve-s always overlap the corresponding passages 36,31 and 38 of the valve casings, but through motion of these sleeves theeffective positions of these ports with relation to the valves 30 isvaried so that the controlling effects of each of the valves is acomposite of the relative motions between the upper ends of the elements5 and 1 and control the passage of fluid pressure from the passage 40into passages and 8|. These passages 80 and 8| lead to ports in a valvecasing within Which is slidably mounted a piston valve 86. This valve 86is provided with annular passages 81, tapered on one side, so that theyact to more or less throttle the passage of fluid, depending upon thedegree of overlap between these passages 8'! and the ports 88 of thecasing. From the valve casing 85 extend the pressure passages 90 and '9!to opposite ends of the pressure cylinders 20 and 21'.

The discharge takes place from opposite ends of the valve casing 85through the passage back to the discharge pipe 50. The position of thevalve 86 which acts as just described to more or less throttle thesupply of pressure to the cylinders 20 and 2|, therefore acts todetermine the speed of travel of the carriages 80 and 64. In accordancewith this invention this speed may be regulated in accordance with apredetermined pattern. For this purpose, the valve 56 has a valve stemI00 connected to the lower end of a bell crank lever I02, fulcrumed atH33 in the upper portion of the tubular casing 2 and the upper arm 403of this bell crank lever has pivoted thereto a rod I04 which extendsdown axially through the element 5 and through the feel-er H. where itis provided with a cam follower head I05 which bears on the upper faceof a cam I06. This cam may have portions of different elevations thereonas shown best in Figures 2 and '10, and as the feeler is caused to tracethe edge of the pattern, this follower I05 rides along the cam Hit andas it changes elevation, it causes the follower 6% to raise or lower,thus changing the axial position of the throttle valve 88 forcontrolling the speed of motion of the carriages ill and Bi and theconsequent speed of motion of the tracer about the pattern. An electricvibrator of any suitable type at 10'! and carried by the bell crank armE83 serves to keep the mechanism sensitive to changing forces since itprevents the various connections from any static friction conditions.

With the arrangement of valves and motors shown, a continuous travel ofthe tracer about a closed cont-our pattern may be effected withoutattention on the part of the operator, the tracer following around thecontour automatically in one direction repeatedly. The reason for thisneed not be further described here, as it forms the subject matter of myapplication for Tracer mechanism, Serial No. 584,003, filed March 21,1945. The means for controlling the speed of traverse is, however,subject matter of the present application.

Further subject matter of this application com.- prises the arrangementof the pattern and its feed relative to the tracer insuch a manner thatthe tool, as it operates on the work, feeds deeper into the work on eachtracing action until it reaches the required depth. Further, in orderthat the tool may operate tobest advantage, it is arranged so that itdoes not cut the full contour of the pattern in the earlier traverses,but makes a straight cut, until stock is removed appreaching the fulldepth which it is desired to control by the contour of the pattern. Forthis purpose the control contour edge initially is formed by a portionof the pattern and a portion of the straight edge of a guard platepartly overlapping the pattern. As the cutting proceeds, this guardplate is retracted by definite increments at the end of each completetraverse of the controlling contour, more or less'uncovering additionalportions of the actual pattern at each cycle until the entire contour iscontrolled by the pattern itself at which time the shield is entirely retracted. The controlling contour of the shield is straight so that asimple continuous depth of cut of the work where the shield is incontrolling position is produced at each actuation. This mechanism isshown in Figures 5 to 11. At H is shown a support for the pattern and towhich the pattern III may be removably secured as by the screws I l2. Asshown this pattern has a pattern opening H3 therethrough having apattern edge H4 which it is desired to reproduce in the work. Thisopening IIB forms a continuous controlling edge for the tracer. The sideH5 is the idle side of the pattern and is merely used to control theidle withdrawal motion of the tool, the active and controlling edge II-4of the pattern being duplicated on all sides of the rotational axiswhere the work is rotating as when carriedby a rotary chuck as is shownin Figure 12. As shown, for example, the work is intended to be a bottlemold having a round internal surface of a contour determined by the edgeII4 of the pattern opening. This pattern opening may be more or lesscovered by the shield II5, which is removably secured to a block H5mounted for motion on the support H0 perpendicular to the edge H5 of thepattern opening. It is arranged to be fed so as to be withdrawn bydefinite increments from overlying relation to the edge II4 of thepattern, and for this purpose it is shown as having threaded engagementwith a feed rod I20 journaled in a frame portion I2I at one end andextending through a portion of the support I I0 at the other, as shownin Figure 6. This feed rod I20 is provided at one end with a beveledpinion I22 which meshes with a bevel gear I23 on a shaft I24. The bevelgear I23 has a crown ratchet gear portion I25 with which may mesh asimilar crown ratchet gear I25 axially movable on the shaft I24 andnormally held pressed into engagement with the crown gear I25 as by aplate spider spring I28. It may, however, be removed from contact withthe crown gear I25 by exerting pressure on the outer end of a releaselever I30 projecting through a slot I3I in an end plate I32 of thesupport III On one face of the support H0 a lever I40 is journaled onthe shaft I24, and secured to this lever I40 is a clutch element I42adapted to engage a mating clutch element I43 at the upper end of asplined collar I44 on which the plate spring I28 is slidable. Rocking ofthe lever I40 imparts rotation tothe clutch portions I42 and I43 androtates the ratchet gear I26.

When this gear I25 is being rotated in a clockwise direction, as shownin Figure II, the crown gear H5 is driven, which drives the beveledgears I23 and I22 and steps the shaft I20 around in a direction towithdraw the shield II5 from overlapping relation to the pattern.Rocking of the lever I40 in the opposite direction, permits the teeth ofthe ratchet gear I25 to ride up against the action of'the plate springI28, slipping over the teeth ofthe crown ratchet gear I25 so that noreverse rotation ofthe feed rod I20 is produced, but at any desired timethe operator may press on the outer end of the lever I30, withdrawingthe ratchet gear I25 from engagement with the crown ratchet gear I25 topermit rotation of the feed rod I20 in either direction desired byturning the hand wheel I45 secured to its end. By this means the shieldmaybe re-set (relative 6 to the pattern) for a new complete cycle ofoperations.

As shown best in Figure 5, the lever I40 extends over the patternopening H3 in position to be engaged by the portion 3 of the tracer ateach tracing cycle of the pattern, thus to rock the lever I by contacttherewith away from a starting position. The location of this startingposition is regulated by the angular adjustment of a se ment I50fulcrumed at I5I on the support H0 and having a series of notches I52 inone edge which may be brought selectively into position to limit thereturn motion of the arm I as produced by a spring I55 secured to a pinI56 carried by the lever I40 at one end and to a fixed pin I51 at theother. The segment I may be secured in an adjusted position by a thumbscrew I58. The tracer in its motion about the pattern at each tracingaction thus swings the lever from a starting full line position shown inFigure 5 to the dotted line position, and produces a retracting motionof the shield, depending in magnitude upon the position of the segmentI50 which determines the initial position of the lever I40 from whicheach swinging motion of the lever is started. Thus in the position s ownin Figure 5, the controlling contour for the tracer is formed partly bythe contour of the opening I I3 of the pattern and partly by thestraight edge of the shield which overlap-s the pattern edge. As theshield is retracted step by step, more and more of the contour of thepattern becomes effective to determine the path of motion of the traceruntil finally the entire contour traced by the tracer is that of thepattern.

Means is shown for stopping retracting motion of the shield II5 after ithas fully uncovered the pattern. This comprises the arm I60 pivoted atItI and having an end I52 adapted to engage a shoulder I53 on the leverI40 and rock the lever I40 to its inactive dotted line position. Thisarm I5!) is moved into this position by pull exerted thereon by thescrew rod I55 having a, nut thereon extending into the slot I55 of thearm I60. This rod I65 is secured in the block IIB which carries theshield H5, but is angularly adjustable to adjustably locate the nut I65, in accordance with the requirements of the particular pattern used.

.A spring pressed plug I08 engaging a recessed shoulder I69 of the rodI55 releasably holds the rod in the desired angular position. When thefull pattern contour has been cleared by the shield, the pattern contourwill be retraced until the machine is stopped.

Since the proportion of the contour traced by the pattern may vary inaccordance with the position of the shield, the contour of the speedcontrolling pattern may also vary across its width as shown in Figure10, so that as the contour control becomes more intricate as more andmore of the pattern edge comes into controlling position, the speedcontrol of the pattern may be correspondingly varied. This is shown, forexample,

. in Figure 10, wherein the slow feed lowest porton of the speed controlplate is more extensive toward the rear portion of the pattern thantoward the forward portion where less of the pattern edge controls thecontour traced.

From the foregoing description of an embodiment of this invention itshould be evident to those skilled in the art that various changes andmodifications might be made without departing from its spirit or scope.

'I claim:

1. In combination, a, tracer mechanism comprising a support, a pair ofelements one within the other, and each pivoted to said support, afeeler carried by one of said elements, said feelercarrying elementbeing pivoted to said support closer to said feeler than the pivot ofthe other of said elements, a pattern having an edge with which a sideof said. feeler may contact, means for moving said support and patternrelatively under control of said feeler as it is moved relative to saidsupport and to said other element by contact of said pattern againstsaid feeler, a cam associated with said pattern, a follower membercarried by said support and extending through said feeler transverse tosaid feeler side and engaging and moving along said cam as said supportand pattern are moved relatively, and means actuated by motion of saidfollower produced by said cam as said support and pattern are movedrelatively for controlling the speed of said moving means.

2. In combination, a pattern presenting a continuous contour edge, asupport, a tracer carried by'sai'd support and having a feeler movablerelative to said support for contact with said edge, power meanscontrolled by changing relation be tween said support and feeler forrelatively moving said tracer and pattern to cause said ieeler to tracesaid edge continuously, and means actuated by such relative motion oneach completion of a -tracing cycle to move at least a portion of saidedge relative to said feeler by a predetermined increment.

:3. In combination, a pattern presenting a con tour edge, a shieldadapted to lap a portion of said shield relative to said pattern to varythe form with a part of said pattern edge a portion of a continuouscontour edge, means for moving said shield relative to said pattern tovary the proportion of its edge and said pattern edge effective to formsaid continuous contour, a tracer, means for moving said tracercontinuously and automatically around the effective contour edge of saidpattern and shield, and means automatically actuated by said tracer asit is moved in a predetermined portion of its path for actuating saidshield-moving means to move said shield outwardly by increments each ofa predetermined amount until the effective contour is produced entirelyby the contour of said pattern.

4. In combination, a pattern having a continuous edge, a shield lappingsaid pattern and having an edge which may with a portion of said patternedge determine a continuous controlling contour, said. shield beingmounted for motion across said pattern, a tracer, means for moving saidtracer in contact with said controlling contour in continuous andrepeated circuits, a movable member normally projecting adjacent to saidcontinuous contour to be engaged and moved by said tracer each time saidtracer reaches a predetermined point in said circuit, and means actuatedby the movement of said member to move said shield outwardly bysuccessive increments to thereby cause increasing lengths of patterncon-tour to be uncovered by said shield and become effective todetermine the contour path described by said tracer.

5. In combination, a pattern having a continuous edge, a shield lappingsaid pattern and having an edge which may with a portion of said patternedge determine a continuous controlling contour, said shield beingmounted for motion across said pattern, a tracer, means for moving saidtracer in contact with said controlling contour in continu- 0115 andrepeated circuits, a movable member normally projecting adjacent to saidcontinuous contour to be engaged and moved by said tracer each time saidtracer reaches a predetermined point in said circuit, means actuated bythe movement of said member to move said shield outwardly by successiveincrements to thereby cause increasing lengths of pattern contour to beuncovered by said shield'and become effective to determine the con tourpath described by said tracer, and means adjustably determining thestarting position of said member in which it is engaged by said tracerto thereby determine the extent of such increments.

6. In combination, a pattern having a continuous edge, a shield lappingsaid pattern and having an edge which may with a portion of said patternedge determine a continuous controlling contour, said shield beingmounted for motion across said pattern, a tracer, means for moving saidtracer in contact With said controlling contour in continuous andrepeated circuits, a movable member normally projecting adjacent to saidcontinuous contour to be engaged and moved by said tracer each time saidtracer reaches a predetermined point in said circuit, means actuated bythe movement of said member to move said shield outwardly by successiveincrements to thereby cause increasing lengths of pattern contour to beuncovered by said shield and become effective to determine the contourpath described by said tracer, means adjustably determining the startingposition of said member in which it is engaged by said tracer to therebydetermine the extent of such increments, means for returnng said memberto starting position after each actuation thereof, and one-Way clutchmeans for causing motion of said member in one direction only to movesaid shield.

'7. In combination, a pattern having a continuous edge, a shield lappingsaid pattern and having an edge which may with a portion of said patternedge determine a continuous controlling contour, said shield beingmounted for motion across said pattern, a tracer, means for moving saidtracer in contact with said controlling contour in continuous andrepeated circuits, at movable member normally projecting adjacent tosaid continuous contour to be engaged and moved by said tracer each timesaid tracer reaches a predetermined point in said circuit, meansactuated by the movement of said member to move said shield outwardly bysuccessive increments to thereby cause increasing lengths of patterncontour to be uncovered by said shield and become effective to determinethe contour path described by said tracer, means adjustably determiningthe starting position of said member in which it is engaged by saidtracer to thereby determine the extent of such increments, means forreturning said member to starting position after each actuation thereof,one-way clutch means for causing motion of said member in one directiononly to move said shield, means actuable to release said one-Way clutchmeans, and means actuable when said clutch means is released to returnsaid shield inwardly to a position of greater obstruction of saidpattern contour.

8. In combination, a pattern presenting a contour edge, a shield adaptedto lap a portion of said pattern and presenting an edge adapted to formwith a part of said pattern edge a portion of a continuous contour edge,means for moving said shield relative to said pattern to vary theproportion of its edge and said pattern edge effective to form saidcontinuous contour, a tracer,

fective contour is produced entirely by the con- 10 tour of said patternto render inoperative said actuating means.

WILLIAM L. TANCRED REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,798,926 Black .1; Mar. 31, 19312,116,593 Bouvier May 10, 1938 2,332,532 Roehm 1 1 Oct 26, 19432,372,427 Johnson Mar. 27, 1945

